Distance-Dependent Metal-Enhanced Intrinsic Fluorescence of Proteins Using Polyelectrolyte Layer-by-Layer Assembly and Aluminum Nanoparticles.
Distance-Dependent Metal-Enhanced Intrinsic Fluorescence of Proteins Using Polyelectrolyte Layer-by-Layer Assembly and Aluminum Nanoparticles.
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DOI：
10.1021/jp2122714
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发表时间：
2012-05-17
影响因子：
3.7
通讯作者：
Ray, Krishanu
中科院分区：
文献类型：
--
作者：
Akbay, Nuriye;Lakowicz, Joseph R.;Ray, Krishanu
先前报道的研究表明，铝纳米结构衬底可以潜在地在金属增强荧光（MEF）应用中找到广泛的用途，特别是在UV或近UV光谱区域朝向生物分子的无标记检测。MEF在很大程度上取决于几个因素，例如纳米结构的化学性质、尺寸、形状及其与荧光团的距离。详细了解MEF及其距离依赖性对于其在生物医学传感中的潜在应用非常重要。我们的目标是利用内在的蛋白质荧光标记的结合试验。这通过使用金属纳米结构而成为可能，所述金属纳米结构提供UV荧光团的局部激发和增强的荧光，并且还将提供一种将表面结合的蛋白质与大量样品分离的方法。我们评估了不同的探针距离等离子体纳米结构的成熟的逐层（LBL）技术。研究蛋白质吸附在不同数量的交替层的聚（苯乙烯磺酸盐）（PSS）和聚（烯丙胺盐酸盐）（PAH）。将牛血清白蛋白（BSA）静电连接到带正电荷的PAH层，将山羊和兔IgG连接到带负电荷的PSS层。我们在距离Al纳米结构表面约9 nm处获得了BSA的荧光强度的最大约9倍增加。在约8 nm的距离处，分别观察到山羊和兔IgG增加约6倍和7倍。所有三种蛋白质的最小寿命比裸对照石英载玻片上的最小寿命短约3倍。用寿命分布模型分析了时间分辨强度衰减，以详细了解距离对金属-荧光团相互作用的影响。本研究表明的距离依赖性的金属增强的蛋白质的固有荧光和潜在的LbL组装控制的金属-荧光团的距离在紫外波长区域。
Previously reported studies indicate that aluminum nanostructured substrates can potentially find widespread use in metal-enhanced fluorescence (MEF) applications particularly in the UV or near-UV spectral region toward label-free detection of biomolecules. MEF largely depends on several factors, such as chemical nature, size, shape of the nanostructure and its distance from the fluorophore. A detailed understanding of the MEF and its distance-dependence are important for its potential application in biomedical sensing. Our goal is to utilize intrinsic protein fluorescence for label-free binding assays. This is made possible by the use of metallic nanostructures which provide localized excitation and enhanced fluorescence of UV fluorophores and will also provide a way to separate the surface-bound proteins from the bulk samples. We evaluated varied probe distances from plasmonic nanostructures by the well-established layer-by-layer (LbL) technique. The investigated proteins were adsorbed on different numbers of alternate layers of poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH). Bovine serum albumin (BSA) was electrostatically attached to the positively charged PAH layer, and goat and rabbit IgG were attached to negatively charged PSS layer. We obtained a maximum of a ~ 9 fold increase in fluorescence intensity from BSA at a distance of ~9 nm from the Al nanostructured surface. Approximately 6- and 7- fold increases were observed from goat and rabbit IgG at a distance of ~8 nm, respectively. The minimum lifetimes were about 3-fold shorter than those on bare control quartz slides for all three proteins. The time-resolved intensity decays were analyzed with a lifetime distribution model to understand the distance effect on the metal–fluorophore interaction in detail. The present study indicates the distance dependence nature of metal-enhanced intrinsic fluorescence of proteins and potential of LbL assembly to control the metal-to-fluorophore distance in the UV wavelength region.
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影响因子：
7.4
作者：
Ray, Krishanu;Szmacinski, Henryk;Lakowicz, Joseph R.
通讯作者：
Lakowicz, Joseph R.
影响因子：
3.7
作者：
Chowdhury, Mustafa H.;Chakraborty, Sudipto;Ray, Krishanu
通讯作者：
Ray, Krishanu
影响因子：
2.7
作者：
D'Auria, S;Bazzicalupo, P;Lakowicz, JR
通讯作者：
Lakowicz, JR
影响因子：
1.9
作者：
Mathias, Patrick C.;Ganesh, Nikhil;Cunningham, Brian T.
通讯作者：
Cunningham, Brian T.
影响因子：
14.8
作者：
Patolsky, Fernando;Zheng, Gengfeng;Lieber, Charles M.
通讯作者：
Lieber, Charles M.